A population of bacteria with an unlimited supply of nutrients will eventually show growth.
Competition, predators, herbivores, parasitism, and overcrowding are density-
limiting factors.
During early human history, the growth rate was low because the birthrate was high and the death rate was

segmentation=endoskeleton=backbone=coelom=tissues

a

explanation:

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".